Spelling suggestions: "subject:"port orford"" "subject:"port erford""
1 |
Variation of drought resistance and root regeneration among genotypes of Port-Orford-cedar (Chamaecyparis lawsoniana)Sharpe, Jodie M. 18 October 2002 (has links)
Drought resistance among genotypes of Port-Orford-cedar (Chamaecyparis
lawsoniana (A. Murr.) Pan., Cupressaceae) seedlings was evaluated both in the field and
in the greenhouse. Field water potentials (��) of 5-year-old seedlings were measured at
two high-elevation plantation sites where summer drought occurs. Measurements of ��
were compared to survival two years prior at the same site. The north coastal breeding
zone 1 had significantly lower mid-day �� and lower survival than the southern interior
breeding zone 6. Percent survival at 3 years was significantly correlated with mid-day ��.
A second assessment of drought resistance was performed in the greenhouse on 1-0
seedlings. Root growth potential (RGP) was measured in the winter under non-stress
conditions and following a drought in the summer. Differences among breeding zones
were opposite in pattern from outplanting measurements of survival and water potential;
therefore, RGP may not be a good predictor of drought resistance or survival among
different genotypes within a single species. Low-elevation, coastal families had greater
root growth than inland, high elevation sources. Greater root growth occurred in
seedlings with more shoot mass. Little regional specialization in RGP across the species'
range was indicated as there was greater variation among families than among breeding
zones. In the summer RGP test following drought, only the two extremes of the range
were evaluated; both north coastal and southern interior families showed decreased root
growth compared to the winter RGP under non-stress conditions. Despite significantly
higher predawn �� in inland, high elevation families, lower elevation coastal families had
significantly more roots. Change in chlorophyll fluorescence yield measured on foliage
of droughted plants was positively correlated with the absolute value of predawn ��;
however, it was not a sensitive predictor of predawn �� (R��=0.06) at the levels used in
this study. Lower levels of �� may be necessary to produce severe stress to damage Port-Orford-cedar foliage. / Graduation date: 2003
|
2 |
Resistance mechanisms of Port-Orford-cedar to Phytophthora lateralisOh, Eunsung 30 November 2004 (has links)
Breeding Port-Orford-cedar for resistance to Phytophthora lateralis, a causal
agent of root disease, begins by screening, through artificial inoculation,
phenotypically resistant trees selected from natural stands. The successful program
selected tolerant or resistant POC parent trees for the purpose of disease management.
Candidate resistant POCs were used in my dissertation to: 1. validate screening
methods such as stem- and root-dip inoculation; 2. test for increased virulence of P.
lateralis; and 3. evaluate detection techniques. The results showed that the established
screening methods were appropriate, and no evidence of changed virulence was found.
A PCR technique was more reliable than other techniques for detection of P. lateralis
in seedlings. An additional test for foliar infection showed that initial penetration
through wounds and natural openings was possible.
POC seedlings and rooted cuttings from resistant and susceptible families were
used to demonstrate resistance mechanisms. In order to explain the mechanisms at the
cellular level, the susceptible response of POC seedlings to P. lateralis was first
observed with light microscopy. Zoospores encysted on lateral roots, germinated, and
penetrated by means of appressoria. Direct penetration between epidermal cells was
common but penetration through epidermal cell walls was also observed. The hyphae
colonized the root cortex inter- and intracellularly. Wound inoculation on stems
resulted in inter- and intra cellular hyphal growth in cambial, sieve, and parenchyma
cells in the secondary phloem.
Several resistance mechanisms were observed: 1) there was a difference in
zoospore attraction between susceptible and certain resistant POCs revealed by
microscopic observation, direct count of encysted zoospores, and quantitative real-time
PCR; 2) the frequency of encystment, penetration, and colonization of resistant
seedlings was much lower than susceptible seedlings, but no differences in infection
pathway were observed by means of light or electron microscopy; 3) collapsed cell
walls were present in resistant POCs showing increased cell wall thickness, wall
appositions, and electron dense materials. / Graduation date: 2005
|
3 |
Geoarchaeology at Tseriadun (35CU7), Curry County, Oregon /Anderson, Frederick C. January 1900 (has links)
Thesis (M.A.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 113-120). Also available on the World Wide Web.
|
4 |
Port-Orford-cedar and Phytophthora lateralis : grafting and heritability of resistance in the host, and variation in the pathogenMcWilliams, Michael G. 06 June 2000 (has links)
Port-Orford-cedar (Chamaecyparis lawsoniana) is a forest tree native to
a small area of Oregon and California. A root disease caused by
Phytophthora lateralis causes widespread mortality of Port-Orford-cedar.
This dissertation examines three important elements of the Port-Orford-cedar
P. lateralis pathosystem related to breeding for disease resistance:
use of resistant rootstocks to maintain genotypes of Port-Orford-cedar for
breeding; the heritability and genetic basis of disease resistance; and
variability in virulence and DNA fingerprint among a sample of P. lateralis
isolates.
Port-Orford-cedar was reciprocally grafted to western redcedar (Thuja
plicata), incense cedar (Calocedrus decurrens), and Alaska yellow-cedar
(Chamaecyparis nootkatensis). Port-Orford-cedar scion graft success was
moderate with western redcedar and incense cedar, but extreme
overgrowth of the rootstock by the scion indicated incompatibility. Xylem
union was good, but phloem union was incomplete or lacking. Nearly all
Port-Orford-cedar rootstocks and seedlings exposed to P. lateralis died of
root disease. Four percent of the Alaska yellow-cedar exposed also died,
confirming this tree as a host for P. lateralis.
Resistance of Port-Orford-cedar to P. lateralis is rare. A small number
of trees have been identified exhibiting resistance. A number of families
were tested to determine the genetic basis for resistance. Estimates of
narrow-sense and family mean heritability of resistance, as exhibited by
restriction of lesion length after inoculation, were determined. Both narrow-sense
and family mean heritabilities were between 0.61 and 0.98 in most
tests. Between 21% and 32% of the variance was due to differences
among families.
Thirteen isolates of P. lateralis were collected from three hosts
throughout the geographic range of the fungus. Variation in growth rate on
artificial media at three temperatures, virulence when used to inoculate
Port-Orford-cedar, and DNA fingerprint were compared. There were
significant differences in growth rate among isolates at 24C, but fewer
differences at lower temperatures and on a rich medium. One isolate
produced significantly shorter lesions in three different inoculation tests.
Isolates differed at only two of 189 bands produced by Inter Simple
Sequence Repeat (ISSR) DNA primers, indicating very little genetic
variation among isolates. / Graduation date: 2001
|
5 |
Improving community profiles for Oregon fisheries and coastal communities through collaboration /Package, Christina. January 1900 (has links)
Thesis (M.A.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 59-61). Also available on the World Wide Web.
|
6 |
Righting history : remembrance and commemoration at Battle RockNading, Linda L. 05 1900 (has links)
Changes to commemorative signage in Port Orford, Oregon, United States, during 1998
and 1999 represent an emerging public acknowledgement of the removal by force of most of the
indigenous peoples of Southwestern Oregon in the 1850s. A wide range of participants, including
local area residents and nonresident members of Native American First Nations, negotiated
changes to signage within a context of controversy. Hegemonic social memory institutionalized
as local history and publicly displayed as text on a historical marker was challenged by an
alternate version of the event commemorated: a conflict between Athapaskans and Euro-
Americans in 1851 at the site now know as "Battle Rock." The alternate version is supported by
oral tradition which is marginalized as a source of knowledge about the past while the official
history has been privileged by repetitious inscription and incorporated commemorative ritual.
Discussion includes the selectivity of public history and the creation of public memory through
commemorative activity in which official and vernacular interests compete. A parallel is drawn
between the remembrance and acknowledgement of events once suppressed and the remembrance
and acknowledgement of marginalized indigenous American First Nations "forgotten" by the
United States federal government. The Confederated Tribes of the Lower Rogue, building
support for legislative acknowledgement of their tribal status, contributed positively to the
production of signage text, an activity which enhanced both their visibility and the visibility and
remembrance of their Athapaskan forebears.
|
7 |
Developing techniques for evaluating the susceptibility of root-disease resistant Port-Orford-Cedar to foliar and stem canker diseases /Martin, Danielle K. H. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 128-132). Also available on the World Wide Web.
|
8 |
Righting history : remembrance and commemoration at Battle RockNading, Linda L. 05 1900 (has links)
Changes to commemorative signage in Port Orford, Oregon, United States, during 1998
and 1999 represent an emerging public acknowledgement of the removal by force of most of the
indigenous peoples of Southwestern Oregon in the 1850s. A wide range of participants, including
local area residents and nonresident members of Native American First Nations, negotiated
changes to signage within a context of controversy. Hegemonic social memory institutionalized
as local history and publicly displayed as text on a historical marker was challenged by an
alternate version of the event commemorated: a conflict between Athapaskans and Euro-
Americans in 1851 at the site now know as "Battle Rock." The alternate version is supported by
oral tradition which is marginalized as a source of knowledge about the past while the official
history has been privileged by repetitious inscription and incorporated commemorative ritual.
Discussion includes the selectivity of public history and the creation of public memory through
commemorative activity in which official and vernacular interests compete. A parallel is drawn
between the remembrance and acknowledgement of events once suppressed and the remembrance
and acknowledgement of marginalized indigenous American First Nations "forgotten" by the
United States federal government. The Confederated Tribes of the Lower Rogue, building
support for legislative acknowledgement of their tribal status, contributed positively to the
production of signage text, an activity which enhanced both their visibility and the visibility and
remembrance of their Athapaskan forebears. / Arts, Faculty of / Anthropology, Department of / Graduate
|
9 |
A New Commons: Considering Community-Based Co-Management for Sustainable FisheriesDohrn, Charlotte L 01 May 2013 (has links)
Commercial fisheries on the West Coast are traditionally managed under large-scale management and conservation plans implemented by state and federal agencies. This scale of management can present obstacles for fishing communities. This thesis examines emerging cases of attempts to define and implement sustainable management of commercial fisheries under a community-based co-management model. In Port Orford, Sitka, San Diego and Santa Barbara, preliminary community-based co-management models are enabling fishing communities to pursue social sustainability through preserving access, participating in local science, and direct marketing for fish products. These communities are actively reshaping traditional models of conceptualizing and managing common-pool resources like fisheries.
|
10 |
Road networks, timber harvest, and the spread of Phytophthora root rot infestations of Port-Orford-cedar in southwest OregonClark, William C. 01 September 2011 (has links)
Phytophthora lateralis is the causal agent of cedar root rot, a fatal forest pathogen whose principal host is Chamaecyparis lawsoniana (Port-Orford-cedar), a predominantly riparian-restricted endemic tree species of ecological, economical, and cultural importance to coastal Oregon and California. Local scale distribution of P. lateralis is thought to be associated with timber harvest and road-building disturbances. However, knowledge of the landscape-scale factors that contribute to successful invasions of P. lateralis is also important for effective land management of Port-Orford-cedar. P. lateralis is able to infest in wet conditions via stream networks (zoospore) and dry conditions via road networks (resting spore). This study tested the hypothesis that vehicles spread P. lateralis by relating its distribution to traffic intensive, anthropogenic disturbances (i.e. a road network, timber harvest) over a 31-yr period in a 3,910-km² portion of the Rogue River-Siskiyou National Forest in the Siskiyou Mountains of Oregon. Indices of road disturbance (presence/absence, configuration, length, density, road-stream network connectivity) and timber harvest (presence/absence, area, density, frequency) were related to locations of infested cedar populations from a USFS survey dataset using a geographic information system (GIS). About 40% of 934 7th-field catchments were infested with the pathogen. Total road length of the study site was 5,070 km; maximum road density was 8.2 km/km2 and averaged 1.6 km/km² in roaded catchments (n = 766). Timber activities extracted 17,370 ha (2,338 cutting units) of forest across 509 catchments; 345 catchments were cut ≥ twice. Maximum harvest density was 0.92 km²/km² ([mean] = 0.04). Both road networks and timber harvest patchworks were significantly
related to cedar root rot heterogeneity. Chi-squared contingency tables showed that infestation rates were 2.2 times higher in catchments with roads compared to roadless catchments and 1.4 times higher in catchments with road-stream intersections compared to those that were unconnected. Infestation was twice as likely in catchments with both harvest and road presence than road presence alone. Single-variable logistic regression showed that a one percent increase in harvest density increased infestation odds 25% and a one-unit (km/km²) increase in road density increased infestation odds 80%. Road and stream network configuration was also important to pathogen distribution: 1) uninfested catchments are most likely to be spatially removed from infested, roaded catchments, 2) only 11% of 287 roaded catchments downstream of infested, roaded catchments were uninfested, and 3) only 12% of 319 catchments downstream of infested catchments were uninfested. Road networks and timber harvest patchworks appear to reduce landscape heterogeneity by providing up-catchment and down-catchment access to host populations by linking pathogenic materials to the stream network. Timber harvest data suggest that while infestation risk to Port-Orford-cedar populations remains high, management policies may have curbed infestation risk in timber-harvested catchments; if this is a result of specific P. lateralis mitigation policies adopted in the late 1980's or broader, region-wide conservation policies (i.e. the Northwest Forest Plan) is yet unclear. / Graduation date: 2012
|
Page generated in 0.0526 seconds